Publications

effects of re-infection with neospora caninum in bulls on parasite detection in semen and blood and immunological responses.

three bulls with experimentally induced primary infection with neospora caninum were re-infected intravenously with 10(8) live n. caninum tachyzoites of the nc-1 isolate at 300 days post-infection to investigate the presence of n. caninum in semen and blood, and the associated immune responses. in parallel, three bulls with experimentally induced primary infection with n. caninum and three non-infected bulls were also monitored. re-infected and infected bulls showed an intermittent presence of n ...

upregulation of cytokines is detected in the placentas of cattle infected with neospora caninum and is more marked early in gestation when fetal death is observed.

the protozoan parasite neospora caninum causes fetal death after experimental infection of pregnant cattle in early gestation, but the fetus survives a similar infection in late gestation. an increase in th1-type cytokines in the placenta in response to the presence of the parasite has been implicated as a contributory factor to fetal death due to immune-mediated pathological alterations. we measured, using real-time reverse transcription-pcr and enzyme-linked immunosorbent assay, the levels of ...

host cells participate in the in vitro effects of novel diamidine analogues against tachyzoites of the intracellular apicomplexan parasites neospora caninum and toxoplasma gondii.

the in vitro effects of 19 dicationic diamidine derivatives against the proliferative tachyzoite stages of the apicomplexan parasites neospora caninum and toxoplasma gondii were investigated. four compounds (db811, db786, db750, and db766) with similar structural properties exhibited profound inhibition of tachyzoite proliferation. the lowest 50% inhibitory concentrations were found for db786 (0.21 microm against neospora and 0.22 microm against toxoplasma) and db750 (0.23 microm against neospor ...

neospora caninum is one of most important causes of abortion in cattle worldwide, and dogs are an important risk factor for n. caninum infection in cattle. antibodies to n. caninum were determined in 184 (126 rural, 58 urban) dogs from the punjab state, india, using commercial monoclonal antibody-based competitive elisa and found in 16.8% of the animals. the prevalence of n. caninum antibodies was significantly higher in rural dogs (21.4%, 27 of 126) than city dogs (6.9%, 4 of 58). to our knowle ...

models for experimental infection of dogs fed with tissue from fetuses and neonatal cattle naturally infected with neospora caninum.

three models were designed to investigate the development and enteroepithelial phase of neospora caninum in dogs, and to induce oocyst production by the parasite. in the first model, three dogs were fed raw fetal bovine tissue on two occasions. the bovine fetal tissue had been stored at 4 degrees c for 14 days and 16 days, respectively, and had tested positive for neosporosis using histopathology and immunohistochemistry. in the second model, nine dogs from the beginning of the experiment until ...

seroprevalence of toxoplasma gondii and neospora caninum infection of cats in hungary.

blood samples were collected from 330 cats in hungary in order to evaluate their seroconversion to toxoplasma gondii and neospora caninum using the indirect fluorescent antibody test (ifat). the overall prevalence of toxoplasmosis was 47.6%, the prevalence being 22.4% among urban, 50% among suburban and 61.3% among rural animals. significantly more cats had high ifat titres (1:640 to 1:5120) in the countryside. female cats were more frequently infected with t. gondii than males (53.3% vs. 39.3%) ...

the development and evaluation of a nested pcr assay for detection of neospora caninum and hammondia heydorni in feral mouse tissues.

the development of a novel nested polymerase chain reaction is described and used for detecting the presence of neospora caninum and hammondia heydorni dna in dna extracted from feral rodent tissues. a unique strategy was used for design of an assay that could be adapted for detecting dna from more than one member of toxoplasmatinae simultaneously with a minimal number of additional steps. the level of sensitivity described for this assay is comparable to real time-pcr and other nested pcr assay ...

the histone-like proteins (hu) belong to a family of dna architectural proteins that stabilize nucleoprotein complexes. we found a putative hu protein (tgglmhmm_3045) in toxoplasma gondii genome that was homologous to the bacterial hu protein. this putative sequence was located in the scaffold tgg_995361 of the chromosome 10. the sequence included the prokaryotic bacterial histone-like domain, kfgslglrrrgervarnprt (id number ps00045). hu protein sequences were also found in plasmodium falciparum ...

brain tissue from 12 aborted bovine fetuses submitted to the wisconsin veterinary diagnostic laboratory revealed histologic lesions that consisted of glial nodules and variable degrees of mononuclear inflammation, microhemorrhage, neuronal necrosis, and cerebral cortical cavitation. a diagnosis of bovine herpesvirus 1 (bhv-1) abortion had been made in all of these cases through multiple testing modalities. brain tissue from 8 of the 12 fetuses was immunohistochemically stained with a monoclonal ...

rhoptry antigens are involved in a variety of cellular functions related to host cell invasion, formation of the parasitophorous vacuole and parasite-host cell interplay. the cdna sequence of one of these antigens, ncrop2 was identified from neospora caninum expressed sequence tags (ests), amplified by reverse transcription-pcr, expressed in escherichia coli as a (his)(6)-tagged recombinant protein (recncrop2) and purified over ni(2+)-affinity chromatography. both recncrop2 and antibodies direct ...

llamas (lama glama) are south american camelids described as intermediate hosts of neospora caninum, toxoplasma gondii and sarcocystis aucheniae. due to the potential role of these protozoan infections as a cause of economic losses, the aim of this study was to determine the seroprevalence for t. gondii, n. caninum and sarcocystis sp. in llamas from argentina. serum samples from 308 llamas (>2 years old) were collected between 2005 and 2007. a total of 55 farms located in six departments of juju ...

detection of neospora caninum in dog organs using real time pcr systems.

neospora caninum is a parasite responsible for paresis in dogs. the dog can harbour enkysted parasites in several organs. the detection of n. caninum was performed using 3 different real time pcr systems all amplifying the nc5 dna region. one system was based on sybrgreen, one on plexor technology and the last on taqman probe. comparison of the three methods indicated that the detection limit was 1 equivalent genome on pure dna but that this detection limit increased in the presence of foreign d ...

retrospective testing of 3,232 serum samples from the general population and 518 serum samples from a high-risk group showed no evidence of human exposure to neospora caninum in england. results were obtained by using immunofluorescence antibody testing and elisa to analyze frequency distribution.

to determine the prevalence of detectable serum igg concentrations in calves prior to ingestion of colostrum and to assess whether a detectable igg concentration was related to dam parity, calf birth weight, calf sex, season of calving, or infectious agents that can be transmitted transplacentally.

ncgra2 as a molecular target to assess the parasiticidal activity of toltrazuril against neospora caninum.

the treatment of neospora caninum infection in the bovine host is still at an experimental stage. in contrast to the in vivo situation, a wide range of compounds have been intensively investigated in cell-culture-based assays. tools to demonstrate efficacy of treatment have remained conventional including morphological and cell biological criteria. in this work, we present a molecular assay that allows the distinction between live and dead parasites. live parasites can be detected by measuring t ...

neosporosis is a parasitic disease caused by a protozoon neospora caninum, which is recognized as an important cause of bovine abortion and canine neuropathy. considering the isolation of n. caninum and the frequent serology in bovines of our region, the objectives of the present trial were to evaluate the occurrence of antibodies anti-n. caninum in dogs of the botucatu range micro region, in the state of são paulo, and its association with gender, age and origin (urban area--exclusively from th ...

seroprevalence and risk factors associated with neospora caninum infection in different dog populations in spain.

in this study, neospora caninum seroprevalence and some associated risk factors were investigated in four different dog populations in spain. n. caninum seropositivity was significantly higher in farm dogs (51%, 51/100) (p<0.001) and lower in household dogs (2.9%, 3/102) (p<0.0001). the seroprevalence in hunting (23%, 23/100) and stray (24.5%, 23/94) dogs was moderate, and no significant differences were observed between these two populations (p>0.05). a significantly higher number of dogs showe ...

neospora caninum is a protozoan parasite and is closely related to toxoplasma gondii, but they are antigenically different. n. caninum and t. gondii infection in a variety of animals such as cattle, dogs, and cats has been reported, but there is little information on the infection of these parasites in domestic yaks. seroprevalence of antibodies to t. gondii and n. caninum in yaks (bos grunniens) from eight regions of qinghai, china were investigated by the indirect agglutination test (iat) and ...

a survey of abortifacient infectious agents in livestock in luzon, the philippines, with emphasis on the situation in a cattle herd with abortion problems.

in the philippines, insufficient consideration has been given to the implementation of systematic control measures against major abortifacient infectious agents in livestock. to elucidate the epidemiology of abortifacient infectious agents in livestock, the prevalence of four abortifacient agents was assessed. initially, a total of 96 cattle including 17 cows with history of abortion were examined in a herd in luzon at the request of the farm owner. six (35.3%) of the 17 aborting cows were found ...

natural postnatal neospora caninum infection in cattle can persist and lead to endogenous transplacental infection.

a serological follow-up study of 3.5 years duration was done of a dairy herd that had experienced a mass seroconversion to neospora caninum following a point source exposure shortly before the 17th of january 2000. a total of 913 blood samples of 244 animals at seven sampling dates were used to investigate the seroprevalence dynamics in the herd. most postnatally infected cattle remained seropositive during the period of investigation but 11 animals became seronegative after 6-27 months indicati ...

high seroprevalence of neospora caninum in the red fox (vulpes vulpes) in the pyrenees (ne spain).

antibodies to neospora caninum were determined in the red fox (vulpes vulpes) in the pyrenees, north-eastern spain. sera from 53 red foxes (29 male and 24 female) were tested using a neospora agglutination test (nat). seroprevalence at dilutions of 1/40, 1/80 and 1/160 was 69.8%, 47.2% and 7.5%, respectively. sex differences were significant only at a dilution of 1:40. the high seroprevalence observed in red fox suggests that this species is highly exposed to n. caninum in this area.

the prevalence of anti-neospora caninum antibodies was determined in serum samples from 110 dogs in south-western poland, using the indirect fluorescent antibody test (ifat). antibodies to n. caninum were found in 18 dogs (16.36%), of which 7 were also positive to toxoplasma gondii. the titres of anti-n. caninum antibodies varied from 1:50 to 1:200.

in september 2004, a neonatal sea otter pup was found alive on the beach in northern monterey bay, ca. efforts to locate the mother were unsuccessful. due to a poor prognosis for successful rehabilitation, the pup was euthanized. postmortem examination revealed emaciation, systemic lymphadenopathy and a malformation of the left cerebral temporal lobe. on histopathology, free tachyzoites and tissue cysts compatible with toxoplasma gondii were observed in the brain, heart, thymus, liver, lymph nod ...

evaluation of an enzyme-linked immunosorbent assay for the serological diagnosis of neospora caninum infection in sheep and determination of the apparent prevalence of infection in new zealand.

neospora caninum has recently been shown to be a cause of abortions of sheep in new zealand. a commercially available enzyme-linked immunosorbent assay (elisa) was validated for use in sheep with sera from experimentally infected sheep. a cut-off threshold was established that demonstrated sero-conversion between 7 and 14 days post-infection. higher inocula led to earlier sero-conversion. this elisa was applied to 640 sera collected from rams across new zealand and 0.625% (+/-0.61%) (4/640) were ...

babesia gibsoni: serodiagnosis of infection in dogs by an enzyme-linked immunosorbent assay with recombinant bgtrap.

the thrombospondin-related adhesive protein of babesia gibsoni (bgtrap) is known as an immunodominant antigen and is, therefore, considered as a candidate for the development of a diagnostic reagent for canine babesiosis. the recombinant bgtrap (rbgtrap) expressed in escherichia coli was tested in an enzyme-linked immunosorbent assay (elisa) for detecting antibodies to b. gibsoni in dogs. the elisa with rbgtrap clearly differentiated between b. gibsoni-infected dog sera and specific pathogen-fre ...

a survey to demonstrate the presence and the extent of neospora caninum infection in dairy cattle was carried out in greece. seven hundred and seventy-seven (777) individual milk samples from all milking cows in 10 dairy herds were tested using an elisa (p38-milk-elisa) and immunoblot analysis. the herd prevalence was 80.0% and 100.0%, while the overall prevalence was 15.2% (ranging between 0.0% and 38.9%) and 27.9% (ranging between 3.4% and 61.6%) based on the results of the elisa and the immun ...

neospora caninum, toxoplasma gondii and eimeria bovis are coccidian parasites of veterinary importance. tachyzoites of n. caninum and t. gondii and sporozoites of e. bovis are able to invade and replicate in endothelial cells in vivo and in vitro. as it holds true for all eukaryotic cells, the survival of parasitized host cells and the parasites themselves should be dependent on ion balances, especially on extra- and intracellular calcium concentrations. addition of the calcium ionophore a23187 ...

serum samples from 251 wild carnivores from different regions of spain were tested for antibodies to neospora caninum by the commercial competitive screening enzyme linked immunosorbent assay (c-elisa) and confirmed by neospora agglutination test (nat) and/or by indirect fluorescent antibody test (ifat). samples with antibodies detected by at least two serological tests were considered seropositive. antibodies to n. caninum were found in 3.2% of 95 red foxes (vulpes vulpes); in 21.4% of 28 wolve ...

influence of neospora caninum infection in balb/c mice during pregnancy in post-natal development.

the influence of neospora caninum infection during pregnancy on the post-natal period has been poorly investigated. in a previous study, we suggested that infection with n. caninum during pregnancy could affect the normal post-natal development of the offspring. for this reason, in the present work we evaluated the influence of n. caninum infection in pregnant balb/c mice at days 0, 7 and 14 of gestation (groups a, b and c, respectively) on the post-natal development of the offspring from birth ...

the differential protein expression profiles and immunogenicity of tachyzoites and bradyzoites of in vitro cultured neospora caninum.

we report a study on the variations in the protein expression profiles of tachyzoites and bradyzoites of neospora caninum. the in vitro stage conversion of n. caninum-infected vero cells was induced by continuous treatment of infected cultures with 70 mum sodium nitroprusside (snp) for up to 9 days. the stage conversion indicated by the expression of the bradyzoite-specific antigen bag1 was analyzed by immunofluoresence assay. morphological changes between tachyzoites and bradyzoites and localiz ...

[epidemiological and financial considerations for the control of neospora caninum on swiss dairy farms].

neospora caninum is widely recognized as one of the most important abortifacients in cattle and causes substantial financial losses to bovine livestock production. this study aimed to calculate the losses caused by n. caninum on swiss dairy farms and to evaluate the efficacy and profitability of the control strategies culling, not breeding replacements and chemotherapy of calves on farm level. three different farm sizes with high, medium and low herd prevalences were defined. epidemiological and ...

capybara (hydrochaeris hydrochaeris) is a large rodent distributed throughout tropical america. antibodies to neospora caninum in 213 feral capybaras from 11 counties of the state of são paulo, brazil, were assessed using the indirect immunofluorescent antibody test (titer >or=1:25) and found in 20 (9.4%), with titers of 1:25 in 4, 1:50 in 7, and 1:100 in 9 animals. this is the first report of occurrence of n. caninum antibodies in capybaras.

toxoplasma gondii and neospora caninum antibodies in dogs from grenada, west indies.

toxoplasma gondii and neospora caninum are structurally similar parasites with many common hosts. the prevalence of antibodies to t. gondii and n. caninum was determined in sera from dogs in grenada, west indies. using a modified agglutination test, antibodies to t. gondii were found in 52 (48.5%) of the 107 dogs, with titers of 1:25 in 17, 1:50 in 19, 1:100 in 7, 1:1,600 in 5, and 1:3,200 or higher in 4. seroprevalence increased with age from 2.2% in dogs <6 mo old to 18.9% in dogs older than 2 ...

the differentiation of transcription between tachyzoites and bradyzoites of in vitro cultured neospora caninum.

interconversion between tachyzoites and bradyzoites of neospora caninum plays a pivotal role in transmission of the parasite. although significant efforts have been made toward understanding the mechanisms that trigger and control stage conversion of the parasite, little is known about this process. we used annealing control primer (acp)-based polymerase chain reaction (pcr) technique to characterize the differences in transcription between tachyzoites and bradyzoites of n. caninum. the in vitro ...

sarcocystis neurona: molecular characterization of enolase domain i region and a comparison to other protozoa.

sarcocystis neurona causes protozoal myeloencephalitis and has the ability to infect a wide host range in contrast to other sarcocystis species. in the current study, five s. neurona isolates from a variety of sources, three sarcocystis falcatula, one sarcocystis dasypi/s. neurona-like isolate, and one besnoitia darlingi isolate were used to compare the enolase 2 gene segment containing the domain i region to previously sequenced enolase genes from neospora caninum, neospora hughesi, toxoplasma ...

deer are considered important intermediate hosts for the coccidian parasites, toxoplasma gondii and neospora caninum. antibodies to n. caninum and t. gondii were determined in sera of 42 mule deer (odocoileus hemionus hemionus) and 43 black-tailed deer (odocoileus hemionus columbianus) from washington state, usa, using direct agglutination test with specific antigens. a titer of 1:25 was considered diagnostic for both parasites. n. caninum antibodies were found in 7 of 42 mule deer and 8 of 43 b ...

toxoplasma gondii is a ubiquitous apicomplexan parasite that can cause severe disease in fetuses and immune-compromised patients. rhoptries, micronemes, and dense granules, which are secretory organelles unique to toxoplasma and other apicomplexan parasites, play critical roles in parasite growth and virulence. to understand how these organelles modulate infected host cells, we sought to identify host cell transcription factors triggered by their release. early growth response 2 (egr2) is a host ...

the role of neospora caninum and toxoplasma gondii in spontaneous bovine abortion in argentina.

the aim of the present work was to evaluate the role of neospora caninum and toxoplasma gondii infections in spontaneous bovine abortions in argentina. based on histopathological results, 70 presumptive cases of apicomplexan protozoal abortion from a total of 666 cases of spontaneous bovine abortion submitted to the national institute of agrarian technology, balcarce, from 1999 to 2007 were included in this study. n. caninum infection was diagnosed by an indirect fluorescent antibody test (ifat) ...

the national herd prevalence and spatial distribution of neospora caninum infected dairy herds in sweden were investigated. the study was based on a bulk milk survey comprising samples from 2,978 herds. test-positive herds were found in all parts of sweden and the overall prevalence of test-positive herds was 8.3% (95% confidence interval = 7.3-9.3%). the presence of spatial autocorrelation was tested using the moran's i test. possible clusters of test-positive herds were identified by applying ...

studies conducted on mithuns maintained at national research centre on mithun, indian council of agricultural research (icar), nagaland, india and mithuns found in free-ranging condition of nagaland revealed that the overall prevalence of antibodies to neospora caninum in mithun was 10% (95% ci=5-15) when detected by a commercially available competitive enzyme-linked immunosorbent assay test. highest (prevalence rate=16, 95% ci=8-24) seroprevalence was found in mithuns above 3 years of age and l ...

the main purpose of this study was to investigate the prevalence of neospora caninum and bovine viral diarrhoea virus (bvdv) in some dairy herds in southern vietnam, and to ascertain whether there were differences in seroprevalences between herds with imported and locally bred cows. serum samples collected on five state farms and 97 smallholder herds were analysed for the presence of antibodies to n. caninum and bvdv. all bvdv antibody-negative sera were further tested by antigen-elisa in order ...

nitazoxanide (ntz) and several ntz-derivatives (thiazolides) have been shown to exhibit considerable anti-neospora caninum tachyzoite activity in vitro. we coupled tizoxanide (tiz), the deacetylated metabolite, to epoxy-agarose-resin and performed affinity chromatography with n. caninum tachyzoite extracts. two main protein bands of 52 and 43kda were isolated. the 52kda protein was readily recognized by antibodies directed against ncpdi, and mass spectrometry confirmed its identity. poly-histidi ...

inoculation of balb/c mice with live attenuated tachyzoites protects against a lethal challenge of neospora caninum.

neospora caninum tachyzoites attenuated through passage in tissue culture were tested for their ability to induce protective immunity against a lethal challenge dose of parasites. balb/c mice were each inoculated with either 1x10(6) live virulent tachyzoites (group 1) or 1x10(6) live attenuated tachyzoites (group 2), while (group 3) received a control inoculum. all mice were each challenged 28 days later with 5x10(6) virulent parasites. histopathological lesions in the brains including necrosis ...

neospora caninum naturally infects many mammal species, but has not previously been demonstrated in birds. we examined sera for n. caninum antibodies from 200 outdoor chickens and from 200 chickens confined indoors in the state of bahia, brazil. seroprevalence was greater in outdoor chickens (23.5% versus 1.5%, p<0.001). pcr testing for n. caninum was positive in six of 10 seropositive chickens. amplicons from two of these were sequenced and had 97-98% nucleotide identity with n. caninum. this f ...

the aim of the study was to diagnose sarcocystis sp. infections in cattle and to detect coinfections by toxoplasma gondii and/or neospora caninum. blood, diaphragm, esophagus, and myocardium from 90 beef cattle from argentina were collected. histopathological, immunohistochemical, polymerase chain reaction assays, and direct microscopical examination were carried out. sarcocysts from myocardium were measured and counted. indirect fluorescent antibody test (ifat) for the three protozoans was perf ...

the extent of parasite-associated necrosis in the placenta and foetal tissues of cattle following neospora caninum infection in early and late gestation correlates with foetal death.

the protozoan parasite neospora caninum is the most frequently diagnosed abortifacient in the uk and a leading cause of abortion worldwide but the mechanisms leading to abortion are not fully understood. the distribution of parasites and the histopathological changes in the placenta and foetus were compared in 12 cows following experimental infection of cattle with n. caninum in early (n=6) and late (n=6) gestation, by pcr, immunohistology, light microscopy and transmission electron microscopy. ...

in vitro analysis of the tat protein transduction domain as a drug delivery vehicle in protozoan parasites.

the present study was undertaken to analyse the capability of hiv-1 derived tat protein transduction domain (ptd) fused with green fluorescent protein (tat-gfp) as a delivery vehicle into a range of protozoan parasites. successful transduction of native purified tat-gfp was observed by fluorescent microscopy in cryptosporidium parvum, giardia duodenalis, and neospora caninum. the ability to transduce peptides and other cargo into protozoan parasites, will greatly assist in the delivery of future ...

quantitative analysis of parasite dna in the blood of immunized and naïve mice after infection with neospora caninum.

real-time pcr was used to study the duration and level of parasitaemia in mice immunized with immune-stimulating complexes (iscoms) containing recombinant ncsrs2, one of the immunodominant surface antigens of neospora caninum. after challenge infection, blood was collected daily for 9 days. during this period the amounts of parasite dna detected in immunized mice were significantly lower (p<0.001), and the duration of parasitaemia appeared to be shorter, than in non-immunized controls. furthermo ...

prevalence of anti-neospora caninum antibodies was measured in serum samples randomly collected from dairy (40 cows from four farms) and beef cattle (120 animals from 12 farms) from the municipality of santarém, pará state, brazil, calculated by using the win episcope 2.0 statistical program. the presence of anti-n. caninum antibodies was determined by indirect immunofluorescence-antibody test with a cut-off value of 1:100. we found that 13 farms (81.25%) showed infection rates above 10%, which ...

isolation and characterization of a bovine isolate of neospora caninum with low virulence.

neospora caninum tachyzoites were isolated from the brain of an asymptomatic naturally infected calf with precolostral-specific antibodies. the new isolate, named nc-spain 1h, was identified as a member of the n. caninum species based on its internal transcribed spacer 1 (its-1) sequence and was genetically characterized using microsatellite markers. multilocus analysis showed that nc-spain 1h was genetically different from other n. caninum isolates. we compared the in vitro tachyzoite yield and ...

neospora caninum infections in chickens have been recently described by epidemiological and experimental approaches, and these birds may be considered natural intermediate hosts of the parasite. it has been postulated that other bird species might perform this role in wildlife as well. to better understand the sylvatic life cycle of n. caninum, further studies are required. in that sense, this work aimed to observe infection kinetics in pigeons experimentally infected with n. caninum. experiment ...

neospora caninum associated with epidemic abortions in dairy cattle: the first clinical neosporosis report in turkey.

neospora caninum, a protozoan parasite, has been considered as one of the most important etiological agents responsible for abortion in dairy cattle throughout the world since it was first identified in dogs in 1988. in this report, characteristics of neosporosis, detected in a dairy cow ranch having epidemic abortions as high as 18.4%, were described. blood samples were collected from 25 infertile or aborted dairy cattle, 6 calves born in 2006 and 40 heifers that were born in 2005 and raised in ...

looks can deceive: molecular identity of an intraerythrocytic apicomplexan parasite in australian gliders.

two yellow-bellied gliders (petaurus australis) had an intraerythrocytic parasite closely related to the cyst-forming coccidia (apicomplexa: sarcocystidae). the parasitaemia persisted for 3 months or more but was observed to clear within 3 years in captivity. the parasite appears not to significantly debilitate its infected host. traditionally, using morphological identification, the intraerythrocytic parasite would have been classified within the hepatozoon species typically found in red blood ...

first isolation of neospora caninum from the faeces of a dog from portugal.

we report the in vitro isolation of neospora caninum from the faeces of a naturally infected 8-year-old male stray boxer from portugal. vero cell cultures were infected using parasite stages obtained after oral inoculation of gamma-interferon knockout mice with 10(2) sporulated oocysts. the isolate was identified by microscopical examination, as well as histological, immunological and molecular methods including a dna-microsatellite-based typing technique, and was subsequently named nc-p1. the d ...

comparison of two pcr protocols for the detection of neospora caninum dna in rodents.

the objective of the present study was, due to increasing interest in the epidemiological role of small mammals as potential reservoir of neospora caninum, to compare two different pcr protocols for the diagnosis of n. caninum in rodents. we tested tissue samples from 50 house mice (mus musculus), 50 rats (rattus norvegicus) and 35 field mice (apodemus sylvaticus). two different pcr protocols based on primer pairs, np4-np7 and np6plus-np21plus, were used for diagnosis on these samples. while the ...

the aim of the present study was to investigate possible relationships between plasma concentrations of prolactin and the following factors throughout gestation in lactating dairy cows: photoperiod, season, milk production, neospora caninum-seropositivity, twin pregnancy, and plasma concentrations of pregnancy associated glycoproteins-1 (pag-1), progesterone and cortisol. pregnancy was diagnosed by trans-rectal ultrasonography on day 40 post-insemination and by palpation per rectum on days 90, 1 ...

effects of a transferring antibody against neospora caninum infection in a murine model.

we investigated the roles of a transferring antibody against neospora caninum infection based on a murine model using recombinant vaccinia virus carrying ncsrs2 gene. higher levels of anti-ncsrs2 antibody were detected in surviving offspring from vaccinated dams than controls while the transferring anti-ncsag1 antibody was detected in the surviving offspring from unvaccinated dams. after mating, the female mice with transferring antibody against n. caninum were challenged with the parasites in m ...

frequency of horizontal and vertical transmission for sarcocystis cruzi and neospora caninum in dairy cattle.

sarcocystis cruzi and neospora caninum infections in cattle are common throughout the world, and cause important economical losses. n. caninum can be transmitted horizontally by ingestion of oocysts or vertically from the infected dam to the fetus via the placenta. vertical transmission for s. cruzi is infrequent and horizontal transmission is considered the most important route of infection. the objectives of this study were to evaluate the frequency of horizontal and vertical transmission for ...

neospora caninum infection is an important cause of bovine abortion. the infection can be transmitted transplacentally or by ingestion of oocysts shed by definitive hosts. there are few reports of dogs naturally shedding n. caninum oocysts and only some oocyst isolates were transferred into cell culture. the aim of the present study was to analyse n. caninum oocysts from the faeces of naturally infected dogs using a microsatellite-based typing technique and to compare them with cell culture-deri ...

inflammatory myopathy associated with several infectious diseases occurs in dogs including those caused by toxoplasma gondii, neospora caninum, ehrlichia canis and hepatozoon canis. however, muscle disease due to leishmania infection has been poorly documented. the aim of this study was to examine the distribution and types of cellular infiltrates and expression of mhc class i and ii in muscle biopsies obtained from 15 male beagle dogs from a breeder group with an established diagnosis of leishm ...

toxoplasma gondii is an obligate intracellular parasite with a variety of hosts, responsible for reproductive problems and economic losses in sheep flocks. neospora caninum was recently identified and its clinical presentation in sheep is similar to that of toxoplasmosis, which can cause repeated abortions, though less frequently in this species. in order to confirm the prevalence of these agents in the city of mossoró, rio grande do norte, brazil, 409 serum samples from adult sheep (364 females ...

evaluation of a srs2 sandwich commercial enzyme-linked immunosorbent assay for the detection of anti-neospora caninum antibodies in bovine and canine sera.

neospora caninum is a parasite responsible for abortion in cows and neuromuscular disease in dogs. serology is the most widely used technique to evaluate the prevalence of n. caninum in different host populations. a sandwich enzyme-linked immunosorbent assay (elisa) based on the use of an anti-srs2 monoclonal antibody was evaluated against the indirect fluorescent antibody test for 100 canine sera and against a well-characterized elisa for 102 bovine sera. in cattle sera, the relative sensitivit ...

a 12-year-old pug presented with a 3-mm corneal mass od. the dog was currently being treated for keratoconjunctivitis sicca (kcs) and pigmentary keratitis ou. a superficial keratectomy followed by cryotherapy was performed od. a histopathologic diagnosis of epithelial dysplasia and suppurative keratitis was made and the lesion resolved. two months later, a yellow/tan conjunctival mass, diffuse chemosis and conjunctival thickening was discovered od. necrotizing conjunctivitis with protozoal paras ...

gerbils (meriones unguiculatus) were inoculated intraperitoneally (i.p.) with neospora caninum tachyzoites to examine parasite distribution and histological lesions at different time points over a 9-day period of infection. gerbils were sacrificed 12 h post-infection (pi), then daily intervals up to day 9 pi. the parasite was detected by pcr assay targeting the nc5 sequence of n. caninum. the parasite was not found in any organs until day 5 pi, however, from day 8 pi onwards, they were detected ...

toxoplasma gondii and neospora caninum antibodies in sheep in the czech republic.

in the czech republic, serum from 547 sheep coming from nine farms was examined for antibodies against parasites toxoplasma gondii and neospora caninum by screening elisa. antibodies against t. gondii were found in 325 sheep (59%) with prevalence ranging from 11% to 96% in different farms. antibodies against n. caninum were found in 63 sheep (12%) with prevalence ranging from 4% to 21% in different farms. mixed infections were found in 53 sheep (10%). it was the first evidence of n. caninum anti ...

short report: prevalence of neospora caninum and toxoplasma gondii antibodies in northern egypt.

in view of the worldwide importance of toxoplasma gondii and neospora caninum and the limited data on the seroprevalence of these parasites in egypt, this study aimed to estimate the prevalence of anti-t. gondii and anti-n. caninum antibodies in rabbits, cattle, and humans. we used elisa methods based on surface antigen 2 of t. gondii (tgsag2t) and surface antigen 1 of n. caninum (ncsag1t). high seroprevalence of t. gondii (51.49%) was detected in pregnant women, and antibodies to n. caninum wer ...

detection of neospora caninum from farm-bred young blue foxes (alopex lagopus) in china.

neospora caninum has been detected in several wild mammalian species, i.e., deer, coyotes, dingoes, and foxes. farm-bred foxes were rarely reported to be affected by the parasite. in this study, we detected for the first time the infection of n.caninum in farm-bred young blue foxes (alopex lagopus) in china. neospora-like tissue cysts were observed in brains and kidneys of the foxes by histopathological and immunohistochemical examinations. one hundred and three sera from the clinically normal v ...

gamma interferon (ifn-gamma) production has been attributed a protective role against abortion in neospora-infected dairy cows. this study investigate possible relationships between plasma levels of the n. caninum-specific immunoglobulin (ig) isotypes igg1 and igg2 and ifn-gamma production throughout gestation in dairy cows naturally infected with the parasite. data were obtained from 31 pregnant neospora-seropositive animals. blood samples were collected on gestation days 40, 90, 120, 150, 180 ...

c57bl/6 mice were infected with neospora caninum tachyzoites during pregnancy, yielding a transplacental infection of developing fetuses. subsequently, congenitally infected newborn mice were treated either once or three times with toltrazuril (or placebo) at a concentration of 31.25 mg compound per kg body weight. both toltrazuril and placebo treatment had no negative effect on newborns, as noninfected treated pups developed normally without differences in mortality and morbidity to matching no ...

marked eosinophilic meningitis or meningoencephalomyelitis (eme) is rarely reported in dogs and the cause is usually undetermined. long-term prognosis for dogs with cerebrospinal fluid (csf) eosinophilia is variable.

our objective was to determine the risk factors associated with the seroprevalence of mycobacterium avium subspecies paratuberculosis (map) in a large number of randomly selected canadian dairy herds, controlling for important confounding variables and co-infections with bovine leukemia virus (blv), bovine viral diarrhea virus (bvdv) and neospora caninum (nc). serum samples from 30 randomly selected cows, where available, in 315 herds from seven provinces were tested for antibodies against blv, ...

neospora caninum is a well known protozoan parasite of domestic and wild animals. neospora hughesi is a closely related protozoan with an unknown life cycle, host range, and infection prevalence. many serologic surveys of n. caninum have been performed without consideration of potential cross-reactions with n. hughesi, which could confound results. the aim of this study was to investigate whether postexposure sera from animals experimentally infected with n. caninum exhibit significant reactivit ...

the genome of the protozoan parasite toxoplasma gondii was found to contain two genes encoding tyrosine hydroxylase; that produces l-dopa. the encoded enzymes metabolize phenylalanine as well as tyrosine with substrate preference for tyrosine. thus the enzymes catabolize phenylalanine to tyrosine and tyrosine to l-dopa. the catalytic domain descriptive of this class of enzymes is conserved with the parasite enzyme and exhibits similar kinetic properties to metazoan tyrosine hydroxylases, but con ...

hammondia heydorni is a coccidian parasite with an obligatory two host life cycle, with dogs and foxes as definitive hosts, and a number of intermediate hosts, including goats. while infection by this parasite seems to be unassociated with any clinical signs, infection by the closely related parasites neospora caninum and toxoplasma gondii can result in abortion, stillbirths and low yielding in caprine herds. the aim of this work was to investigate the frequency of goats infected with h. heydorn ...

seroprevalence of neospora caninum and toxoplasma gondii antibodies in white-tailed deer (odocoileus virginianus) from iowa and minnesota using four serologic tests.

the white-tailed deer (odocoileus virginianus) is considered one of the most important wildlife reservoirs of neospora caninum and toxoplasma gondii in the us. sera from white-tailed deer from minnesota and iowa were tested for antibodies to n. caninum by four serologic tests including the indirect fluorescent antibody (ifa) test (cut-off 1:25), neospora caninum agglutination test (cut-off 1:25), an enzyme-linked immunoabsorbent assay, and western blot (wb). sera were also tested for antibodies ...

crab-eating fox (cerdocyon thous), a south american canid, as a definitive host for hammondia heydorni.

hammondia heydorni is a cyst forming coccidia closely related to other apicomplexans, such as toxoplasma gondii, neospora caninum and hammondia hammondi with a two-host life cycle. dogs and other canids as red foxes (vulpes vulpes) and coyotes (canis latrans) may serve as definitive hosts for h. heydorni. sporulated oocysts are infective for cattle, sheep and goats, which may serve as intermediate hosts. herein, we describe the ability of crab-eating fox (cerdocyon thous), a wild carnivore that ...

neospora caninum is an intracellular parasite that causes major economic impact on cattle raising farms, and infects a wide range of warm-blooded hosts worldwide. innate immune mechanisms that lead to protection against this parasite are still unknown. in order to investigate whether myeloid differentiation factor 88 (myd88) is required for resistance against n. caninum, genetically deficient mice (myd88(-/-)) and wild type littermates were infected with live tachyzoites and the resistance to in ...

stage-specific expression of nc sag4 as a marker of chronic neospora caninum infection in a mouse model.

neospora caninum infection persists throughout the life of its intermediate host due to the conversion of tachyzoites to slowly dividing bradyzoites that encyst in the brain. this event results in persistent n. caninum infection in bovine herds and partially explains the poor efficacy of many chemotherapeutic agents and vaccine formulations. thus, there is a need for greater understanding of the tachyzoite-to-bradyzoite conversion mechanisms. here we studied for the first time the transcription ...

cpg-odn combined with neospora caninum lysate, but not with excreted-secreted antigen, enhances protection against infection in mice.

cpg oligodeoxynucleotides (odn) have shown to be potent immunoadjuvants for several pathogens, but there is limited information concerning their use in immunization protocols against neosporosis. this study aimed to evaluate the potential of cpg-odn combined with neospora lysate antigen (nla) or excreted-secreted antigen (ncesa) to induce protective immune response against neospora caninum infection in mice. c57bl/6 mice were vaccinated subcutaneously three times at 2-week intervals with nla, nl ...

bovine neosporosis, caused by neospora caninum is a leading cause of abortion in cattle. we postulated that neosporosis could lead to fetal death and mummification. fifteen mummified fetuses were tested by polymerase chain reaction (pcr) for the mutation in the bovine slc35a3 gene that causes complex vertebral malformation (cvm) and the pnc-5 gene which identifies n. caninum infection. dna was extracted from the mummified fetuses and the sex of the mummies was determined by pcr. the cvm mutation ...

we investigated the protective potential of recombinant his-tagged antigens recncmic1, recncmic3 and recncrop2, applied either as single vaccines or as vaccine combinations, in balb/c mouse models for cerebral and fetal infection. subsequently, mice were mated and challenged by i.p. inoculation of 2 x 10(6)neospora caninum tachyzoites at day 7 of pregnancy. the mortality and morbidity of adult mice (non-pregnant and dams) and of the newborn pups was studied for a period of 40 days following birt ...

the immunogenicity of a dna vaccine expressing the surface protein ncsrs2 of neospora caninum was studied in balb/c mice. the ncsrs2-encoding dna was obtained by pcr amplification of the ncsrs2 orf gene from the p43 plasmid encoding the n. caninum surface protein ncsrs2, ligated to the mammalian expression vector pcdna3.1/zeo(+) and propagated in e. coli dh5alpha to produce the n. caninum ncsrs2 dna vaccine. balb/c mice were immunised by two intramuscular injections of the dna vaccine with or wi ...

effects of crossbreed pregnancies on the abortion risk of neospora caninum-infected dairy cows.

previous studies have shown that the use of beef bull semen significantly reduces the rate of abortions due to neospora caninum in artificially inseminated (ai) seropositive dairy cows. in addition, certain beef breeds could be more resistant to n. caninum infection and abortion than others. the aim of the present study was to determine whether different crossbreed pregnancies, those derived from limousin, charolais, piedmontese or belgian blue semen, carry different risks of abortion in neospor ...

according to current knowledge, sexual development of the apicomplexan parasite neospora caninum takes place in the canine intestine. however, to date there is no information on the interaction between the parasite and the canine intestinal epithelium, and, next to the clinical and in vivo research tools, an in vitro model comprised of canine intestinal cells infected with n. caninum would be very helpful for investigations at the cellular level. following the isolation of cells of neonatal cani ...

four bulls and 56 heifers seronegative to neospora caninum were used to determine the feasibility of venereal transmission in bovine neosporosis under natural conditions. bulls were experimentally infected with 10(8) live n. caninum tachyzoites. two of them with the nc-1 isolate and the other two with the nc-spain-7 isolate. after 13 months of initial infection, each bull was re-infected with the same isolate and dose. the experiments were carried out from march to september during 2006 and 2007 ...

serum samples from 1028 sheep were collected from 32 herds within federal district, in the central region of brazil. the samples were examined by indirect fluorescent antibody test (ifat) using sera diluted 1:64 and 1:50 as cut-off values for the detection of antibodies against toxoplasma gondii and neospora caninum, respectively. the observed prevalence for t. gondii infection was 38.22% (26.81%<ci 0.95<49.62%), and the titers ranged from 64 to 65536. the observed prevalence for n. caninum infe ...

molecular approaches to diversity of populations of apicomplexan parasites.

apicomplexan parasites include many parasites of importance either for livestock or as causative agents of human diseases. the importance of these parasites has been recognised by the european commission and resulted in support of the cost (cooperation in science and technology) action 857 'apicomplexan biology in the post-genomic era'. in this review we discuss the current understanding in 'biodiversity and population genetics' of the major apicomplexan parasites, namely the eimeria spp., crypt ...

the apicomplexa have some of the most comprehensive and integrated proteome datasets of all pathogenic micro-organisms. coverage is currently at a level where these data can be used to help predict the potential biological function of proteins in these parasites, without having to defer to measurement of mrna levels. transcriptomic data for the apicomplexa (microarrays, expressed sequence tag (est) collections, serial analysis of gene expression (sage) and massively parallel signature sequencing ...

seroprevalence of neospora caninum antibodies in beef cattle in three southern states of mexico.

the aims of the present study were to examine the seroprevalence of neosporosis in beef herds from three southern states of mexico and determine the association with several risk factors. a cross-sectional serological survey for neospora caninum was carried out by sampling a total of 596 animals from 31 herds in chiapas, veracruz, and yucatan states and tested using an elisa assay (idexx) to detect anti-n. caninum antibodies. the overall prevalence was 11.6%, (95% ci: 0.93-0.14), however, the pr ...

neospora caninum, potential cause of abortions in dairy cows: the current serological follow-up in slovakia.

neosporosis is considered to be a contributing risk factor for abortions in dairy cows and other farm animals and has negative economic impact on their breeding. in respect of the rapid spread of neosporosis in herds throughout the world, our aim was to detect the prevalence of anti-neospora antibodies in cows post-abortion (pa) (pa group n=716) and in cows without any reproduction problems (control group n=247) on large breeding farms from eastern slovakia. the overall mean seropositivity in pa ...

from 2003 through 2007, serum samples from 5594 dairy and beef heifers and cows in argentina were assessed to quantify the association between presence of neospora caninum antibodies and history of abortion, type of exploitation, and age category of animals. animals with a history of abortion were 85% more likely (p<0.01) to be positive to n. caninum than animals without a record of abortion. for a given category (age) of animals, being in a dairy operation increased the odds of being n. caninum ...